The present invention relates to an apparatus for winding a thread reserve and a cross-wound bobbin onto a bobbin tube.
With textile machines, for example spinning and twisting machines, the thread is continuously delivered to a bobbin device disposed at each spinning or twisting location, where it is generally wound up to form a cross-wound bobbin. In order for the continuous processing of cross-wound bobbins to provide a knotting possibility in the form of a thread reserve, and to draw off the cross-wound bobbin to the last winding in a disruption-free manner, the thread reserve should comprise a thread that has the same spin or thread twist as does the thread that on the whole is wound up to form the cross-wound bobbin.
A further requirement is that the placement of a thread onto an empty bobbin tube, and the formation of the thread reserve, should be carried out in a substantially automated manner in order on the one hand to relieve the operating personnel and on the other hand to obtain uniform, reproducible results, even for successive winding processes.
With the apparatus pursuant to DE 2 711 024 C2, the start of the thread is brought into the vicinity of a bobbin tube that is provided with holes by means of a gripper arm. By means of a suction line that extends in the bobbin creel arm, and openings disposed at the end face of the centering plate, air is drawn out of the bobbin tube through the centering plate. Due to the air that flows in subsequently from the outside through the holes of the bobbin tube, the start of the thread is drawn into the interior of the bobbin tube, where it is held securely in place, so that the subsequent thread can be wound onto it by rotation of the bobbin tube. Since the start of the thread that is drawn into the bobbin tube is essentially held in place only loosely within the bobbin tube by the intake or suction air, there is no defined binding location of the following spun or twisted thread that would ensure that upon formation of a thread reserve, the latter would have a spin or thread twist that corresponds precisely to that of the thread wound to form the cross-wound bobbin. Aside from this, this known reference describes no measures for building up a thread reserve.
It is therefore an object of the present invention to provide an extensively automatically operating apparatus for first winding a thread reserve and subsequently a cross-wound bobbin onto a bobbin tube such that the thread that is wound to form a thread reserve has a twist that corresponds to the twist of the thread wound to form the cross-wound bobbin.